29-04-2017, 09:17 AM
1
ExpoDisc 77mm 2.0 Neutral and Portrait White Balance Filter
Exciting day today, Waiting for a parcel via Parcel Force. Ok what is it? I hear you ask.it is an ExpoDisc 77mm 2.0 Neutral and Portrait White Balance Filter.
That has you stumped ? yes ?
let me try and explain.
Digital camera have preset filters such as sun shade flash cloud and indoor lighting varients. Also auto white balance where the camera has to guess at the amount of light (grey) hitting the sensor for the right colour.
As a camera initially sees everything in grey it it guesses the nearest grey to the scene. could be 30% or 10% grey a wild guess at best.
The correct amount of grey is 18% to get the best colours out of a camera. So what this filter does is give the correct amount 18% grey then you get true colours.
Light varies, so in any given situation this filter fits onto the camera lens and with the camera pointing towards the light source can capture 18% grey (the correct amount) thus making another filter in a camera preset filter range instead of shade sun etc.
This then gives the true colours and overrides what the camera thinks is ok.
This 15 second operating setup of the camera can save hours of work with editing to get right what the camera misreads.
Hopefully when i have had a play with it I will be able to put up the difference this filter makes
Which had the expodisk fitted??? . No editing involved apart from resizing
Thee are several tuts in youtube for anyone interested
29-04-2017, 03:51 PM
2
Re: ExpoDisc 77mm 2.0 Neutral and Portrait White Balance Filter
Originally Posted by realspeed
->
Exciting day today, Waiting for a parcel via Parcel Force. Ok what is it? I hear you ask.it is an ExpoDisc 77mm 2.0 Neutral and Portrait White Balance Filter.
That has you stumped ? yes ?
let me try and explain.
Digital camera have preset filters such as sun shade flash cloud and indoor lighting varients. Also auto white balance where the camera has to guess at the amount of light (grey) hitting the sensor for the right colour.
As a camera initially sees everything in grey it it guesses the nearest grey to the scene. could be 30% or 10% grey a wild guess at best.
The correct amount of grey is 18% to get the best colours out of a camera. So what this filter does is give the correct amount 18% grey then you get true colours.
Light varies, so in any given situation this filter fits onto the camera lens and with the camera pointing towards the light source can capture 18% grey (the correct amount) thus making another filter in a camera preset filter range instead of shade sun etc.
This then gives the true colours and overrides what the camera thinks is ok.
This 15 second operating setup of the camera can save hours of work with editing to get right what the camera misreads.
Hopefully when i have had a play with it I will be able to put up the difference this filter makes
Which had the expodisk fitted??? . No editing involved apart from resizing
Thee are several tuts in youtube for anyone interested
29-04-2017, 07:09 PM
3
Re: ExpoDisc 77mm 2.0 Neutral and Portrait White Balance Filter
That takes me back. In the old days when I used to develop my own colour slides, in order to get the correct exposure from the outset you placed an 18% grey card next to the subject matter and get a light reading from that first then lock in the exposure settings before moving to the subject itself.Printing from negatives was similar to get the exposure right. The idea was that you got a negative which had a fair distribution of colours on it and then putting a set of filters into the enlarger, the image was projected through through a diffuser on to transparent acetate sheet which had a range of different colours on it. This was placed on top of the photographic paper, an exposure made and when developed the nearest shade of grey to the 18% sample card provided in the kit gave you the correct set of filter strengths to put in the enlarger. Happy days.
Never occurred to me that they use the same 18% system in modern DSLRs
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